1. Introduction

2. Leptospirosis

Encounter
1. Prevalent in tropical and subtropical regions
2. Contact with soil or water contaminated with urine from an infected animal
Entry
1. Pass through mucous membranes or skin abrasions
2. Incubation from 7-13 days
Spread/Multiplication
1. Can spread to any organs, particularly kidneys
2. May be found in CSF
Damage
1. High fever
2. Headache
3. Myalgia
4. Conjunctival suffusion
5. Hemorrhage
6. Abdominal pain
7. Vomiting
8. Anicteric leptospirosis in 90%
  1. Less severe
  2. Lower fever, meningitis, uveitis, and rash
9. Icteric leptospirosis
  1. Jaundice, hepatitis, renal failure, pulmonary and visceral hemorrhage, and carditis
  2. Rapidly fatal if untreated
Virulence Factors
1. Some strains produce hemolysin
2. LPS
Diagnosis
1. Clinical
2. PCR or ELISA
Treatment
1. Penicillin or doxycycline
2. May require hemodialysis
Outcome
1. 40-70% fatality with icteric leptospirosis
2. May cause residual headaches, uveitis, or psychologic disturbances

Encounter
1. Transmitted through Ixodes ticks
2. Often in late spring or early summer
3. Most common on northeast coast and around the Great Lakes
Spread/Multiplication
1. Spread through skin over several days
2. Spread to over organs over weeks
Damage
1. Early localized days after bite
  1. erythema migrans - non-itchy bulls-eye rash
2. Early disseminated infection days to weeks after bite
  1. fever, malaise, arthralgia, neurologic manifestations, meningitis, and peripheral neuropathy
3. Late Lyme disease months to years after bite
  1. arthritis with joint swelling in large joints
  2. polyradiculopathies or other PNS or CNS manifestations
  3. inflammatory skin lesion that leads to skin atrophy
Virulence Factors
1. Binds to complement factor H and to factor H-like protein to inhibit alternative complement pathway
2. Alter Vls locus to evade immune system
3. Few surface proteins therefore difficult for immune system to recognize it
Diagnosis
1. Often diagnosed clinically based on symptoms and patient history
2. ELISA to detect IgM or IgG antibodies
Treatment
1. Oral doxycycline is drug of choice
2. IV ceftriaxone if serious nervous system involvement
Outcome
1. Not fatal and usually clears with treatment
2. Rarely develop antibiotic treatment-resistant chronic Lyme arthritis, which may be autoimmune-related

Encounter
1. Sexually transmitted or transplacental spread
Spread/Multiplication
1. Initially reside extracellularly, but spread by lympathic drainage
Damage
1. Primary syphilis 10-90 days after encounter
  1. chancre at site of inoculation
2. Secondary syphilis 6 weeks to 6 months after primary infection
  1. 50% of affected individuals
  2. early systemic spread to lymph nodes, liver, joints, muscles, and distal skin
  3. disease abates in 1/3 of affected patients and no bacteria remain
3. Tertiary syphilis years to decades after initial infection
  1. vasculitis, inflammation, gummas, and liver destruction
  2. tabes dorsalis, dementia, and motor function impairment
  3. aortic valve insufficiences and aortic aneurysms
Virulence Factors
1. Does not produce virulence factors or toxins
2. Few surface proteins therefore difficult for immune system to recognize
Diagnosis
1. Serology tests for anti-cardiolipin antibiodies with RPR or VRDL tests
Treatment
1. Very sensitive to penicillins therefore treat with long-acting penicillins

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